It is known to those skilled in the art of orthodontics to use a bracket adhered to a tooth to engage an arch wire. The brackets, limited by current processes of manufacturing, have a constructive arrangement forming a body and a base (which may be composed of a single piece too) and, even with the development of new technology, little or almost nothing has changed, within the opening of the “channel” from the anterior face. The recent greatest revolution was the introduction of a lid or clip that holds the arch wire into the slot, actively or passively.
This traditional structure, although it is still being used extensively, is inconvenient because of the lack of flexibility when it comes to changing the tooth position established by the bracket, which means that if the orthodontist needs to change the torque or inclination of the bracket or arch wire, to adjust the position of the desired tooth, he or she will have to bend the wire or replace the bracket.
Another inconvenience (when it comes to the traditional twin brackets that are still being widely used in the market) results from the need for a metal or rubber ligatures to secure the wire to the bottom of the channel, due to the fact that the channel has an opening, with angulation and inclination predefined to each bracket, without possibility of change or modify except by changing the whole bracket. Finally, the only two ways to increase or reduce the force transmitted from the arch wire to the tooth is by changing the wire diameter or material composition.
There are also newer brackets known as self-ligature brackets, which have a lid that functions as the ligature. This system is divided between passive systems that do not push the arch wire against the bottom of the slot, and active or interactive systems, which push the arch wire against the bottom of the slot, some only from a certain arch wire diameter. However, this system follows the logic of having a single pre-defined angulation and inclination prior to bonding the bracket to the tooth, and cannot be modified except by the exchange of the bracket.
Stifter, U.S. Pat. No. 2,908,974 shows a bracket system of female and a male connecting member which are attachable in order to form an orthodontic assembly capable of receiving a certain arc wire, for example. In case there is a need to change the position of a tooth or bend this arc wire, it is always necessary to withdraw the male part, which is always taken laterally and then the removal of the arch wire; then the replacement of this arc, besides also requiring the use of a ligature (metallic or elastic) to hold the arch wire into the bracket.
The main focus of the invention proposed by Stifter: a male and female system that enables a change in position of the arch wire follows a traditional and extremely old way of thinking in the dental field, wherein a metal wire “ligature” attaches to a bracket with the aid of pliers and has its ends twisted, cut and accommodated. The current version of this ligature is made of elastic material. But this system, besides being laborious, accumulates dirt around the bracket, compromising hygiene and increasing the friction between the arch wire and the bracket, causing the need for greater use of force for tooth movement. Stifter also shows the possibility of changing the inclination of the male part that shows an opening to the buccal (or opposite to the female side) or a completely closed slot. However, this operation requires that the arch wire to the removed or all ligatures must be removed before and after the later placement of the arch wire in its position, re-tied one by one. In practice, one of the most common reasons for emergencies in the orthodontic practice is that these wire tips, that were initially cut, get out of the position where they were placed and hurt the inner lining of the mouth, causing injuries, pain and discomfort to the patient.
Cordato, U.S. Pat. No. 7,033,170 shows securing the arch wire by introducing a side “clip” in the slot of the bracket so as to combine the two fixed walls of the bracket together with the two movable walls of the “clip”, forming a rectangular tunnel in which the arch wire is passed through, ruling out any possibility of adjusting the angulation of the tooth in relation to the vertical axis, in the internal and external sense. This also includes the use of a tighter or looser “clip”, which together with the bracket, can give more or less freedom to the arch wire. This feature would allow the arch wire to be positioned with greater freedom in relation to the tooth, however without the characteristic of active control (i.e., determining whether the tooth will be moved left or right, forward or backward).
Another problem encountered is when the orthodontist faces crowded teeth that are the main aim of patient when asking for the orthodontist assistance, in order for the teeth to be correctly aligned in the oral cavity. Prior solutions would also have disadvantages in their techniques in most situations where there is a situation of dental crowding, since it is totally impractical for the technique of Stifter which brings the internal fitting member connecting male to the female bracket that can only be performed sideways due to the shapes of the parts and when the needed lock is required, one must use a ligature; the same occurs in Cordato, where the “clip” must be inserted on the inside via the laeral face of the part.
Therefore, the previous proposals have disadvantages in regards to their use that are overcome by the invention herein proposed. Significantly, its lock, besides having other advantages, is located externally and buccally or labially, without the need for additional ligature, allowing simultaneous control of the tooth position.
Regarding the torque control that refers to angulation of the tooth in respect to the vertical axis, in the lingual (internal) X buccal-labial (external) sense of the oral cavity and inclination control of the tooth in relation to its position in relation to the mesiodistal direction, we can conclude that Stifter could achieve this level of control, but the procedure requires removal of the arch wire, exchange of the male-part, arch wire replacement and relocation of the male part, which are extremely complex, laborious for the professional performing it and totally uncomfortable for the patient that will stay longer on the chair and will be much longer in the treatment room. In this scenario, the technique used by Cordato would never allow such angulation or inclination, since there are always 2 affixed walls of the bracket that join the 2 movable walls of the “clip”, to then create the tunnel in which the arch wire will pass through, wherein this characteristic does not allow the total control to be achieved due to the absence of three-dimensional control.